Hardest HC boss in 10 man which is not the Sha HC

Well I think that lots of people have killed heroic bosses in this tier. It is widely known that Sha HC is the hardest of this tier, but what about the other bosses? Which you think to be the second hardest one bestides Sha?

As for me I would vote on Shek'zeer at the moment ( I havent tried Tsulong, lot of people say that he is really tough) not because of the difficulity but rather the insane burst, which she makes in P1: if your healers don't know how to do everything perfectly ( 4 healer fight, gonna love it) then it is a wipefest.

We 3 healed it in our off night 10 man (1 disc ofc). It really doesn't need 4 healers - p3 damage is fairly light as long as dispels are quick. Also, if you 3 heal and use potions twice before p3 you might skip the 2nd windblade phase, which makes the fight very easy.

If your dps isn't good enough for that and you have to 4 heal it then yea, I can see it being 2nd hardest.

We 3 healed it in our off night 10 man (1 disc ofc). It really doesn't need 4 healers - p3 damage is fairly light as long as dispels are quick. Also, if you 3 heal and use potions twice before p3 you might skip the 2nd windblade phase, which makes the fight very easy.

If your dps isn't good enough for that and you have to 4 heal it then yea, I can see it being 2nd hardest.

It's not the phase 3 which required 4 healers. You needed 4 healers if you wanted to reach phase 3, then you could loot.

Empress 10m hc pre nerf... The nerf along with gear to make it with one phase 2 and 3 healers makes it so easy, us healers fall asleep there every week. (Having a Prot Pala tanking the small adds helped us tremendously before they nerfed Prot paladins. Our prot pala did more HPS in p2 than all 4 of our healers combined during that part, and was usually 2nd or 3rd on the healing meter when fight was over. Now Prot Palas are nerfed, though.)

Now it's definetively Lei Shi 10m hc. Thats one of the few bosses we wipe on during farm, and it certainly is the only fight that ooms us. (2 heal since beginning)

With my experience, certain bosses start off really hard, but then become easily farmed in future weeks. Others are easy and stay easy, and some can be easy one week and give us trouble the next. Even each guild will have trouble on one boss when other guilds don't, which is because of composition or strengths and weaknesses. Some guilds may have great healers, while others don not.
For example, Empress was killed in 8 attempts on our first night, and every week after, we have either 1 shot it or spent 2-3 attempts. Also Imperial gave us the most trouble out of any fight when we were learning it, and took us about 2 nights of attempts to down it, and now we 1 shot it every week. However, Amber Shaper only took us about 1 full night of attempts, and we have been one-shotting it every week since, but tonight we spent about 7-9 attempts just to get it down.
As for learning the fights, and getting them down for the first time, Imperial was the hardest. Empress was a complete joke, and Sha of Fear right now feels like a joke. We are actually doing really well with it, and should down it this week or next. Sha of Fear just has a low kill rate because there are so many bosses before it, and guilds tend to struggle on a lot of different fights just to get to it. They build it up in their head that it will be a really hard fight.
As for downing the fight each week consecutively, and smoothly, overall I would say that, for this tier, Spirit Kings was the hardest. It was the biggest road block for a lot of guilds, especially pre-nerf, and is a very involving fight. Obviously, with better gear and MSV being a lower quality raid, the fight is a joke now, but at the time and overall difficulty for this tier, Spirit Kings is the winner.

I'm sure it is Amber-shaper or Spiritkings if you go by tries. It's way more challenging for 10 people to learn how to use that thing than everything else in this content. Sha was rather easy and disappointing with a boring phase2 and once you had the buff from phase2 this boss became very boring.

Heroic Will was also really challenging for those who killed it really early with nearly no gear.

Nice, thank you for your different opinions!
It seems that every guild is struggling with different bosses in different times then. For us Ambershaper was really easy and downed him in one raid day and we are on the 2nd raid day on Empress, tho she seems to finallydie this week ^^